i) Field of the Invention
The present invention relates to pulp forming machines.
ii) Summary of the Prior Art
In the prior art pulp forming machines are known in which a pulp slurry is sucked onto a porous forming mould to provide initial forming of a moulded pulp product. This product is subsequently pressed between two heated mould halves to dewater the product.
For production efficiencies machines are preferred to have more than one product item being formed simultaneously. To achieve this the forming platens are provided with an array of fixed mould halves. In prior art pulp forming machines the fixed mould halves present difficulties of accurate cooperation with fixed mould halves of other platens with which they are to cooperate due to often significant temperature differences at different stages in the forming process. The temperature differential leads to misalignment of mould halves which were intended to cooperate when platens are brought together
It is an object of the present invention to provide a pulp forming machine and/or parts thereof which will at least go some way to overcoming the above disadvantages and/or which will at least provide industry with a useful choice.
In a first aspect the invention consists in a pulp forming machine including a forming head comprising;
a platen,
a plurality of mould carriers,
mould carrier support means connecting each said mould carrier to said platen and allowing said mould carrier and said platen to transmit forces perpendicular to the general plane of said platen, but to allow movement and expansion of each said mould carrier in the general plane of said platen, and
mould carrier to mould carrier locating means to locate the mould carriers during a forming process to align moulds carried thereon with co-operating moulds of a co-operating platen.
In a further aspect the invention consists in a pulp forming machine including a forming head comprising:
a platen,
a plurality of mould carriers,
each said mould carrier including one or more connection posts protruding from the back face thereof and passing within the body of said platen, each said post including a mould carrier facing engagement surface, and
laterally movable post engagement means in said body of said platen, having a securing face facing away from the respective said mould carrier, lateral movement of said post engaging means effecting change of said assembly between a first condition wherein said securing surface of said post engagement means and said engagement surface of said post bear against one another and said mould carrier is supported against movement away from said platen, and a second condition wherein said post engagement means is not engaged with said posts and said posts may be withdrawn from within said platen.
In a still further aspect the invention consists in a pulp forming station including an upper mould carrying platen,
a lower mould carrying platen,
platen movement means connected to one of said upper and lower mould carrying platens for bringing said platens together, and
clamping means for pressing said platens together including a plurality of clamping engagements on one said mould platen and a plurality of actuating means on the other said mould platen for drawing against said clamping engagements in use.
In a still further aspect the invention consists in a pulp forming machine including one or more forming stations and one or more mobile platens supported from above, said mobile platens supported substantially centrally from and movable along the line of an elevated beam running the length of said machine.
In a yet further aspect the invention consists in a pulp forming machine incorporating one or more of the inventions set forth in the above paragraphs.
In a yet further aspect the invention consists in a method of demoulding platens of a pulp forming machine comprising the steps of:
bringing an upper and a lower mould platen incorporating complementary mould halves together,
linking corresponding pairs of moulds and/or mould carriers associated with each said platen together,
releasing the lower said set of mould carriers and/or moulds from engagement with said lower platen,
moving apart said upper and lower mould platens,
moving laterally said upper mould platen to a detooling station,
introducing a mould and/or mould carrier support below said upper platen at said detooling station,
releasing said upper mould carriers and/or moulds from said upper platen, and
vertically separating said upper platen from said mould support.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.